Faulty intake manifold tuning valve or its actuator, with an internal short or open circuit; Damaged, chafed or corroded wiring in the valve control circuit, including a short to voltage; Poor connection or corroded terminals at the valve connector or control unit plug; Fault in the vacuum or electric solenoid that operates the tuning valve, where fitted; Faulty driver circuit inside the engine control unit; Outdated control unit software, only where the manufacturer has issued an update for this fault.

P0665

Intake Manifold Tuning Valve Control Circuit High Bank 2.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
6: AreaComputer and output circuits
65: FaultThe specific fault in that area

What it means

P0665 is the generic code for a high signal in the control circuit of the intake manifold tuning valve on Bank 2. The engine control unit commands the valve, which changes the intake runner length or airflow path to suit engine speed, and it saw a circuit voltage higher than expected for the commanded state. This points to an electrical fault in the circuit rather than a proven mechanical fault, though the exact valve layout depends on the engine.

Symptoms

Engine warning light on
Loss of power or flat spot at certain revs
Rough or uneven idle
Poor fuel economy
Reduced mid-range or top-end performance
Possible hissing or rattling from the intake manifold area

Possible causes

Faulty intake manifold tuning valve or its actuator, with an internal short or open circuitlikely
Damaged, chafed or corroded wiring in the valve control circuit, including a short to voltagelikely
Poor connection or corroded terminals at the valve connector or control unit plugpossible
Fault in the vacuum or electric solenoid that operates the tuning valve, where fittedpossible
Faulty driver circuit inside the engine control unitrare
Outdated control unit software, only where the manufacturer has issued an update for this faultrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, such as engine speed, load and temperature, when the fault set.
Check for related codes, especially other tuning valve, bank 1 or supply voltage faults, as these may point to a shared wiring or power fault.
Visually inspect the valve, its connector and the wiring loom for chafing, heat damage, corrosion, water ingress or poor locking of the plug.
Using a scan tool with bidirectional control, command the valve on and off and listen for or watch the actuator move.
Check the supply voltage and earth or control signal at the valve connector against the manufacturer's wiring diagram.
Measure the valve or solenoid resistance and compare it with the manufacturer's specification, which varies by engine.
Test the control wire for a short to voltage and for continuity back to the control unit with the connectors disconnected.
If the wiring and valve test fine, check the control unit connector pins and then consider a control unit fault, following manufacturer procedure.

How to fix

Replace the intake manifold tuning valve or actuator if it fails electrical or operation tests.
Repair or replace damaged wiring and fix any short to voltage in the control circuit.
Clean or repair corroded terminals and replace faulty connectors, ensuring they lock fully.
Replace the control solenoid or repair the vacuum supply where the system uses one.
Repair or replace the engine control unit only after all wiring and components are proven good.
Apply a manufacturer software update if one is published for this fault.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but expect reduced performance and economy. Get it checked soon, as a stuck valve or wiring fault can get worse and may affect other systems.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.